Will preamp manufacturers tell you if the model is phase inverse?

I know for Prima Luna no. For my current CJ ET3se the manual mentions phase inversion.

In my vast experience, most manufacturers will say something about it in the manual if it does invert phase.  If it is not mentioned, then usually it does not invert phase.  Of course, there are exceptions.

I remember the older cj preamps stated it in the manual, but in really small fine print.

Virtually certain that the RP-1 inverts phase--confirm with John Rutan (audioconnection on this board).  I think the added complication with that preamp is that the phono pre-amp adds another stage of inversion, bringing you back into phase.  If you care about that sort of thing (I do, others don't), it means you're switching speaker wires around when you play records....

it means you’re switching speaker wires around when you play records....

Or you could just invert the phono leads at the arm/cartridge and be done. I once owned a preamp that only inverted the phono stage, the line stage was normal.

Ah, yes!  Good point.